Magnification viewer

ABSTRACT

A housing for a magnification loupe is provided having a body portion for an eyepiece lens and a nose portion for an objective lens. The body portion for the eyepiece lens includes outer circumferential threads over which the objective nose portion fits. The objective nose portion includes a pin slot defining an arc across the body of the nose. The arc is configured such that a pin may be secured through the holes in the nose piece to co-act with the threads of the eyepiece body such that radial movement is prohibited.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority of ProvisionalApplication Serial No. 60/069,496, filed Dec. 15, 1997.

BACKGROUND OF TEE INVENTION

1. Field of the Invention

The present invention relates to magnification viewers worn by surgeonsand dentists. In particular, the invention relates to an assembly foroptical viewers or loupes which allow a user to adjust an objective lensat a predetermined distance from an eyepiece lens to vary the focalpoint.

2. Description of the Related Art

Magnification viewers generally including pairs of magnification loupes,are worn by dentists and surgeons for extended periods of time duringclinical procedures, so as to provide clarity of view while avoiding ahunched-over position that can result in debilitating neck and backstrain, which can have an adverse effect on the success of theoperation. The viewers permit the clinician to operate at a greaterworking distance from the patient. Higher magnification viewers alsoreduce the clinician's exposure to aerosols. Because clinicians usemagnification viewers during surgery and other procedures requiringmanual precision, it is important that they be light-weight, comfortableand have good clarity and wide field of vision while providing highmagnification and good depth of field.

Surgical telescopes may be attached to a spectacle frame in one of twomanners: outside-the-carrier or prescription lens (“outside-the-lens”),on an adjustment mechanism that provides for adjustment of theinterpupillary distance and convergent angle variability, orthrough-the-lens, permanently cemented and fixed in place. As notedabove, magnification viewers used by surgeons and dentists typicallyhave a predetermined magnification. Neither the working distance nor themagnification may be changed without a tedious process of replacingeither individual lens elements or the entire optical loupes themselves.Accordingly, there is a need for a simple method for changing themagnification of viewers being worn by a surgeon or dentist, as well asfor altering the working distance of viewers having a particularmagnification.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the invention, a housing for amagnification loupe is provided having an eyepiece portion for aneyepiece lens and a nose portion for an objective lens. The body portionfor the eyepiece lens includes outer circumferential threads over whichthe objective nose portion fits to enable the distance between thelenses in the body and nose portions to be varied in order to vary theworking distance of the loupe. The objective nose portion includes apair of apertures for receiving a pin. The apertures are configured suchthat the pin forms a chord across the body of the nose portion andco-acts with the threads of the eyepiece body forming an axialmechanical stop to prevent the nose portion from being removed duringadjustment.

Magnification loupes according to the present invention include a nosehousing for an objective lens and a body housing for an eyepiece lens.The system is configured such that the magnification of themagnification loupe may be changed simply by removing the nose housingand replacing it with another. The working distance for a particularmagnification level may be adjusted by threading or unthreading the nosehousing.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention is obtained when thefollowing detailed description is considered in conjunction with thefollowing drawings in which:

FIGS. 1a-1 c are perspective views of a magnification loupe inaccordance with the present invention illustrating the connection of apair of magnification loupes according to an embodiment of the presentinvention secured through the lenses of a pair of spectacles forming amagnification viewer in accordance with the present invention;

FIG. 2 is a perspective view of magnification loupes according to thepresent invention secured to an adjustable nose piece for securing to apair of spectacles;

FIG. 3a is an exploded perspective view of the magnification loupeassembly for the magnification loupes of FIGS. 1 and 2;

FIG. 3b is a side cross-sectional view of the magnification loupe ofFIG. 3a;

FIG. 4 is a side-elevation view of a nose housing forming a portion ofthe magnification viewers of FIGS. 1 and 2;

FIGS. 5a and 5 b are side-cross-sectional views and detailside-cross-sectional views, respectively, of the housing of FIG. 4;

FIG. 6 is a top plan view of the nose housing of FIGS. 4 and 5;

FIG. 7 is a side elevational view of the eyepiece housing of FIGS. 1 and2;

FIGS. 8a-8 c are side cross-sectional views of the housing of FIG. 7,including details thereof;

FIG. 9 is a top plan view of the eyepiece housing of FIGS. 7 and 8;

FIG. 10 is side elevational view of a spacer for the magnificationloupes of FIGS. 1 and 2;

FIG. 11 is a side cross-sectional view of the spacer of FIG. 10;

FIG. 12 is a top elevational view of the spacer of FIGS. 10 and 11;

FIG. 13 is a side elevational view of a field stop of the magnificationviewer of FIGS. 1a-3 b;

FIG. 14 is a side cross-sectional view of the field stop of FIG. 13;FIG. 15 is a top plan view of the field stop of FIGS. 13 and 14;

FIG. 16 is a side elevational view of an objective lens retainer ring ofthe magnification loupes of FIGS. 1a-3 b;

FIG. 17 is side cross-sectional view of the objective retainer of FIG.16;

FIG. 18 is a top plan view of the objective retainer of FIGS. 16 and 17;

FIGS. 19a and 19 b are exploded perspective views of a prism assemblyfor the magnification loupes of FIGS. 1a-3 b;

FIGS. 20a, 20 b and 21-22 illustrate a prism for the prism assembly ofFIGS. 19a and 19 b;

FIGS. 23-26 illustrate the prism assembly of, FIGS. 19a and 19 b;

FIGS. 27-29 illustrate the roof prism of the prism assembly of FIGS. 19aand 19 b;

FIGS. 30-32 illustrate the second prism of the prism assembly of FIGS.19a and 19 b;

FIG. 33 is a diagram of the optical layout of the magnification loupe ofFIGS. 1c, 3 a and 3 b ; and

FIG. 34 is an optical layout diagram of the optical loupe of FIGS. 1a, 1b and 1 c according to an alternate embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings and with particular attention to FIGS. 1aand 1 b a magnification viewer 10 including a pair of spectacles 100with through-the-lens magnification loupes 106 a, 106 b. As illustrated,the magnification loupes 106 a, 106 b are of the Keplerian design. Thespectacles 100 include carrier lenses 102 a, 102 b. The carrier lenses102 a, 102 b may be either plano lenses or prescription lenses. Themagnification loupes 106 a, 106 b are fixed in the carrier lenses 102 a,102 b to provide stereoscopic vision. The magnification loupes 106 a,106 b are set at the user's interpupillary distance converging to adesired working distance, for example, anywhere from 12 to 24 or 13-21inches. As will be discussed in greater detail below, from a selectedworking distance, the user has the option to vary the viewing distanceby rotating the objective lens housing or nose housing 108 a, 108 b ofeach magnification loupe 106 a, 106 b to the desired focus. As will bediscussed in more detail below, one of the objective lens housings 108a, 108 b formed and the eyepiece housings 110 a, 110 b are formed withthreads, which cooperate with a pin attached to the other housing toform a threaded coupling. The eyepiece housings, 110 a, 110 b, in turn,are secured to the carrier lenses 102 a, 102 b by various techniques,including a friction fit on with an adhesive, such as epoxy.Alternatively, the eyepiece housings 110 a, 110 b may be secured to thecarrier lenses 102 a, 102 b by way of known threading on the outside ofthe eyepiece housings 110 a, 110 b matching threading on the carrierlenses 102 a, 102 b.

As will be discussed in greater detail below, magnifications of 3.3×,3.8×, 4.3× and 4.8× are possible according to one embodiment of theinvention to provide a wide range of selection. For each magnification,working distances of about 12″, 16″ and 24″ may be provided. The carrierlenses 102 a, 102 b normally enable a user to focus comfortably at 500mm, about −2D, a typical reading distance. The magnification loupes 106a, 106 b, as will be discussed in greater detail below, further includea prism system (FIGS. 19-32). Each magnification loupe uses an identicalprism and eyepiece lens system. For different magnifications, only theobjective lenses are changed. The user may create depth of field byadjusting the focal distance of each eye depending upon the operationbeing performed. The focuses of each of the magnification loupes 106 a,106 b may be changed independently. The aperture for the objective lenshas been reduced in size to provide an increase in depth of field athigh magnifications while still providing substantial light.

Turning now to FIG. 2, an alternative configuration of the magnificationloupes 106 a, 106 b of FIGS. 1a and 1 b is illustrated. It is noted thatfor the lens system 20 of FIG. 2, the optical configurations of themagnification loupes 206 a, 206 b are different from thethrough-the-lens configuration of FIG. 1, but the barrels or housingsare similar in that only the objective lens need be changed to providedifferent magnifications. The prism and eyepiece remain the same. Theoptical system 20 of FIG. 2 includes a pair of spectacles 200 includinga pair of carrier lenses 202 a, 202 b and a binocular magnificationviewer 25, including a pair of magnification loupes 206 a, 206 b. Asdiscussed in U.S. Pat. No. 5,667,291, the binocular magnification viewer25 may be attached to the spectacles 200 by a pivot member 250.Alternatively, the magnification loupes 206 a, 206 b, may be mountedclose to the spectacle lenses, for example, about 0.5 mm from thecarrier lenses 202 a, 202 b. The pivot member 250 in turn, is attachedto a bridge 258 which includes a bridge adjustment knob 252 foradjusting a pair of extension of arms 254, 256 to enable theinterpupillary distances of the loupes 206 a, 206 b to be adjusted. Theinterpupillary distance of the magnification loupes 206 a, 206 b mayfurther be adjusted by knobs 260 a, 260 b. The binocular magnificationviewer 25 may be secured to the spectacles 200 by way of a clip, screws,glue or other known methods.

MECHANICAL CHARACTERISTICS

Turning now to FIG. 3a, an exploded perspective view of themagnification loupes 106 in accordance with the present invention areshown. The magnification loupes 106 a, 106 b include a nose or objectivehousing 108 a and a body or eyepiece housing 110 a. As illustrated, theobjective housing 108 a includes a frusto-conical front portion 350 anda generally cylindrical rear portion 352. It is noted that the housing108 may be of different shapes; thus, FIG. 3 is exemplary only. Theobjective housing 108 a includes a pair of apertures 304. The apertures304 are configured to receive a pin 302 such that the pin 302 defines achord across the cylindrical rear portion 352 of the objective housing108 a. More particularly with reference to FIG. 3B, the objectivehousing 108 a includes an interior surface 308 which,engages an exteriorsurface 307 of the eyepiece housing 10 a. Spiral threads 306 re formedinto the surface of the eyepiece housing.111 a. The apertures 304 arelocated in the objective housing 108 a so that the pin 302 engage thespiral or threads 306. The pin 302 enables a threaded coupling betweenthe two housing 108 a and 108 a even though only one housing 110 a isformed with threads. The threaded coupling between the housings 106 aand 108 a permits the working distance of the loupes 106 a, 106 b to beadjusted by relating the objective housing 108 a relative to theeyepiece housing 110 a, which in turn, varies the distance between theeyepiece and objective lenses which varies the working distance of theloupes 106 a, 106 b.

Another important aspect of the invention, is that the configurationallows the magnification of the loupes 106 a, 106 b to be rather easilychanged. More particularly, the pin 302 may be removably mountedrelative to the objective housing 108 a or fixedly mounted with the useof epoxy. Depending on the embodiment, the magnification of the loupecan be rather easily changed at the factory or by the user or both. Inparticular, as will be discussed in more detail below, the magnificationof the loupe 106 a, 106 b is changed simply by changing the objectivelens in the loupe 106 a, 106 b. The objective lenses are easily changedby removing the pin 302 which enables the objective housing 108 a to beremoved so that the objective lens 312 can be removed and replaced. Aswill be discussed in more detail below, an important aspect of theinvention relates to the ability to vary the magnification of the loupe106 a, 106 b.

As best illustrated in FIG. 3b, the objective lens 312 is configured torest within a first interior portion 360 of the objective housing 108 a.The interior portion 360 includes a circumferential slot 311 for seatingan O-ring 310 therein. The objective lens 312 rests against the O-ring310 and is engaged in place-by a threaded retainer ring 314. Theretainer ring 314 includes external threads to engage correspondingthreads on the interior portion 360 of the objective housing 108 a.

Additional details concerning the objective housing 108 a areillustrated in FIGS. 4-6. For example, the exterior of the objectivehousing 108 a may include a knurled portion 109 for easy engagement ofthe objective housing 108 a to the eyepiece housing 110 a.

The eyepiece housing 110 a, illustrated in greater detail in FIGS. 7-9,includes a forward engagement portion 307 and a rear cylindrical portion309. As discussed above, the forward engagement portion 307 includesthreads 306 for engagement with the pin 302. It is noted that accordingto one embodiment of the invention, the threads 306 are circular threadsrather than notched or V-shaped threads so as to more effectively engagethe pin 302. The eyepiece housing 110 a includes internal threads 340positioned where the engagement housing 307 meets the rear cylindricalportion 309. The threads 340 are configured to engage the threads 341 ofthe field stop 318 (FIGS. 3a, 3 b). The rear cylindrical portion 309 ofthe eyepiece housing 110 a further includes a circumferential platform344, configured to receive a lens 332 for example, a prescription lens.The lens 332 is held in place against the platform 344 in contact with aprescription lens O-ring 330 and a retainer ring 334, which has externalthreads that engage the internal threads 342 of the eyepiece housing 110a. In the embodiment illustrated, the rear cylindrical portion 309 ofthe housing 110 a is configured to be fastened to the carrier lens 102 aby way of a suitable adhesive, such as epoxy. In an alternativeembodiment, however, the rear cylindrical portion 309 may be providedwith threads to engage similar threads in the carrier lens.

The forward engagement portion 307 of the eyepiece housing 110 a isfurther configured to receive a prism assembly 316 (FIGS. 19a, 19 b).The prism assembly 316 includes a prism holder 317 including a pair ofarms 319 a, 319 b, a base portion 321, and is adapted to fit within thehousing 110 a. The forward portions of the arms 319 a, 319 b includecircular cutout portions 323 a, 323 b respectively, to engage a holderring 402. The holder ring 402 is configured, when attached in place(such as by an adhesive), to secure the prism elements 404, 406, 408.According to one embodiment, the prism elements (FIGS. 20a-22) form aroof-pechan prism separated by a spacer 408. The spacer 408 is formed,for example, of a blackened ridge metal with a six millimeter diameterhole centered on the optical axis. The prism surfaces on opposite sidesof the spacer are generally parallel. The individual elements of theroof pechan prism 404, 406 and 408 are illustrated in FIGS. 25-27 and28-30, respectively. The prism elements are formed from Schott BAK4 orLAK10 glass.

Turning back to FIGS. 3a -3 b, the base of the prism assembly 316 isconfigured to rest against a rear wall 351 of the forward engagementportion 307 at approximately the position where it engages the rearcylindrical portion 309. A field stop 318 (FIGS. 13-15) having externalthreads 341 engages the corresponding internal threads 340 of thehousing 110 a. The field stop 318 further includes internal grooves 343.The rear cylindrical portion 309 of the housing 110 a further houses theeyepiece lens elements. As shown, in FIG. 36 the eyepiece lens includeselements 320 and 324, separated by a spacer 322. The spacer 322 isillustrated in FIGS. 10-12 and may include internal concentric grooves329 which form a light baffle. Finally, the eyepiece lens 324 restsagainst the platform 344.

As shown in FIGS. 3a and 3 b, the exterior of the engagement housing 307includes a pair of concentric circumferential grooves 325, 327configured to receive the O-rings 326, 328 respectively. The O-rings326, 328 additionally function to self-center the objective housing 108a and hence, the objective lens 312 relative to the eyepiece housing 110a.

While the configuration described and shown with regard to FIGS. 3a-3 brelates to a through-the-lens viewer, a similar configuration may-beused in the outside-the-lens system shown in FIG. 2. Such a system maybe used without a prescription lens and, as will be described in greaterdetail below, a different eyepiece system.

OPTICAL CHARACTERISTICS

Turning now to FIG. 33, a diagram illustrating the optical layout of themagnification loupe 106 a, 106 b of FIGS. 1a, 1 b, 3 a and 3 b is shown.The magnification loupe 106 a, 106 b as illustrated in FIG. 33 includesa two-element objective lens including elements I-II and including athree-element eyepiece including elements III-V. R1, R2 etc., representthe radii of respective refractive surfaces; S1-S5 represent thethickness of the air spaces; and T1, T2, etc., represent the thicknessesof the lens elements. As discussed above, according to one embodiment ofthe invention, magnifications of 3.3×, 3.8×, 4.3× and 4.8× are provided.All magnifications use the same prism and eyepiece lens system. As shownin FIGS. 28 and 32, the prior angle α may be used in the range 45°-49°,preferably 48° to increase the optical performance of the device whilethe prism angle B (FIG. 32) may be selected to be 24°. Thus, a commoneyepiece housing 110 a and optical elements included therein may be usedfor all of the magnifications. As discussed above, only the objectivelens needs to be changed in order to alter the magnification.

The user may create a depth of field by adjusting the focal distance ofeach eye differently depending on the operation being performed. Forexample, a heart surgeon may wish to view the entire depth of the heartat high magnification previously unattainable in conventionalmagnification systems where depth of field is limited. This can beaccomplished by adjusting the focus of the left eye one-inch beyond theright. When both eyes are then opened, the heart can be viewed in itsentirety. However, a dentist may only require the depth of the coronalportion of the tooth to be in focus and thus, would only separate thefocus by a millimeter or two. Alternatively, both magnification loupescan be precisely focused at the same distance for procedures requiringthe highest resolution. The following exemplary fields of view may beprovided:

93 mm@3.3×@16″WD

82 mm@3.3×@16″WD

72 mm@3.3×@16″WD

65 mm@3.3×@16″WD

Exemplary construction data for a magnification loupe built according tothe embodiment shown in FIGS. 1a-3 b are given in Tables I-XII. Theradii, thickness, and separation dimensions are given in millimeters.Roman numerals identify the lens elements in their respective order fromthe objective side to the eyepoint side; nd represents the refractiveindex of each element; ν_(d) is the abbe dispersion number; R1, R1,etc., represent the radii of the respective refractive surfaces in orderfrom the objective side to the eyepoint side; T1, T2, etc., representthe thicknesses of the lens elements from the objective side to theeyepoint side; S1, S2 represent the thicknesses of air spacesrespectively from the objective side to the eyepoint side measured alongthe optical centerline. Again, it is noted that the prism/objectivedistance 51, can differ by about 2.5 mm if BAK4 glass is used, ratherthan LAK10, as in the tables.

FIG. 34 illustrates an embodiment of the present invention having longeye relief characteristics. Again, the system shown in FIG. 34 employsthe same prism and eyepieces, but separate objective doublets for eachlevel of magnification. The objective doublets and the prism, however,are the same as for the through-the-lens embodiment shown in FIG. 33.Additionally, only the eyepiece lens is changed from thethrough-the-lens configuration. As compared the embodiment of FIG. 33,eye relief—the distance to exit pupil—has been improved from about 17.8mm to about 22.8 mm.

In particular, the viewer according to FIG. 34 includes the two-elementor doublet objective including elements I-II and a four-element eyepiecelens including elements III-VI. R1, R2, etc., again represent the radiiof respective refractive surfaces; S1 and S2 represent the thicknessesof the air spaces; and T1, T2, etc., represent the thicknesses of thelens elements.

Exemplary construction data for loupes according to the embodiment ofFIG. 34 are given in Tables XIII—XXIV.

TABLE I 3.3X (12″ WD) Element Glass nd νd Radius Thickness Diameter Sep.I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 6.96 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE II 3.3X (16″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 5.01 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE III 3.3X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 3.63 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE IV 3.8X (12″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.04 4.0 13.4 BAH 27 R₂ = 14.61 II Ohara1.8052 25.4 R₂ = 14.61 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 12.38 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE V 3.8X (16″ WD) Element Glass nd νd Radius Thickness Diameter Sep.I Ohara 1.7015 41.2 R₁ = 42.19 4.0 13.4 BAH 27 R₂ = 14.61 II Ohara1.8052 25.4 R₂ = 14.61 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 9.92 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE VI 3.8X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.04 4.0 13.4 BAH 27 R₂ = 14.61 II Ohara1.8052 25.4 R₂ = 14.61 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 8.02 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE VII 4.3X (12″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 50.15 4.0 13.4 BAH 27 R₂ = 16.00 II Ohara1.8052 25.4 R₂ = 16.00 1.5 13.4 PBH6W R₃ = 47.79 Prism A BAK4 1.568856.13 S₁= 18.07 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE VIII 4.3X (16″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 50.15 4.0 13.4 BAH 27 R₂ = 16.00 II Ohara1.8052 25.4 R₂ = 16.00 1.5 13.4 PBH6W R₃ = 47.79 Prism A BAK4 1.568856.13 S₁ = 15.56 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15.4BAH10 R₈ = 94.04

TABLE IX 4.3X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 50.15 4.0 13.4 BAH 27 R₂ = 16.00 II Ohara1.8052 25.4 R₂ = 16.00 1.5 13.4 PBH6W R₃ = 47.79 Prism A BAK4 1.568856.13 S₁ = 13.13 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK41.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅ = 17.86 III Ohara 1.805225.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IV Ohara 1.4875 70.2 R₅ =13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.6700 47.3 R₇ = 15.59 3.0 15. 4BAH10 R₈ = 94.04

TABLE X 4.8X (12″ WD) Element Glass nd νd Radius Thickness Diameter Sep.I Ohara 1.7015 41.2 61.12 4.0 13.4 BAH 27 II Ohara 1.8052 25.4 16.98 1.513.4 SFL6 Prism A BAK4 1.5688 56.13 S₁ = 25.16 LAK10 1.7200 50.41 S₂ =3.41 S₃ = 7.04 Prism B BAK4 1.5688 56.13 S₄ = 0.05 LAK10 1.7200 50.41 S₅= 17.86 III Ohara 1.8052 25.4 R₃ = 44.00 2.0 15.4 PBH6W R₄ = 13.00 IVOhara 1.4875 70.2 R₅ = 13.00 6.5 15.4 FSL5 R₆ = 13.00 V Ohara 1.670047.3 R₇ = 15.59 3.0 15.4 BAH10 R₈ = 94.04

TABLE XI 4.8X (16″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 61.12 4.0 13.4 BAH 27 II Ohara 1.8052 25.416.98 1.5 13.4 SFL6 Prism A BAK4 1.5688 56.13 S₁ = 21.23 LAK10 1.720050.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK4 1.5688 56.13 S₄ = 0.05 LAK101.7200 50.41 S₅ = 17.86 III Ohara 1.8052 25.4 R₃ = 44.00 2.0 15.4 PBH6WR₄ = 13.00 IV Ohara 1.4875 70.2 R₅ = 13.00 6.5 15.4 FSL5 R₆ = 13.00 VOhara 1.6700 47.3 R₇ = 15.59 3.0 15.4 BAH10 R₈ = 94.04

TABLE XII 4.8X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 61.12 4.0 13.4 BAH 27 II Oshara 1.8052 25.416.98 1.5 13.4 SFL6 Prism A BAK4 1.5688 56.13 S₁ = 18.22 LAK10 1.720050.41 S₂ = 3.41 S₃ = 7.04 Prism B BAK4 1.5688 56.13 S₄ = 0.05 LAK101.7200 50.41 S₅ = 17.86 III Ohara 1.8052 25.4 R₃ = 44.00 2.0 15.4 PBH6WR₄ = 13.00 IV Ohara 1.4875 70.2 R₅ = 13.00 6.5 15.4 FSL5 R₆ = 13.00 VOhara 1.6700 47.3 R₇ = 15.59 3.0 15.4 BAH10 R₈ = 94.04

TABLE XIII 3.3X (12″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₃ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 6.96 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = 0.5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XIV 3.3X (16″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 5.1 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆= 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XV 3.3X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₃ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 3.63 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XVI 3.8X (12″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 12.38 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XVII 3.8X (16″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 9.92 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XVIII 3.8X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 8.02 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XIX 4.3X (12″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 18.7 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17 5 S-LAM2 R₉ = 25.11

TABLE XX 4.3X (16″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 15.56 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XXI 4.3X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 13.13 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ 22.8 III Ohara 1.5410 47.2 R₄= PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XXII 4.8X (12″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 25.16 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XXIII 4.8X (16″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 21.23 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.541 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

TABLE XXIV 4.8X (24″ WD) Element Glass nd νd Radius Thickness DiameterSep. I Ohara 1.7015 41.2 R₁ = 42.19 3.5 13.4 BAH 27 R₂ = 12.45 II Ohara1.8052 25.4 R₂ = 12.45 1.5 13.4 PBH6W R₃ = 36.00 Prism A BAK4 1.568856.13 S₁ = 18.22 LAK10 1.7200 50.41 S₂ = 3.41 S₃ = 2.33 Prism B BAK41.5688 56.13 S₄ = .5 LAK10 1.7200 50.41 S₅ = 22.8 III Ohara 1.5410 47.2R₄ = PLANO 3.0 12.0 S-TIL2 R₅ = 12.61 IV Ohara 1.923 21.3 R₅ = 12.61 1.515.4 PBH71 R₆ = 12.61 V SCHOTT 1.5168 64.2 R₇ = 10.06 7.1 15.4 BK7 R₆ =12.61 VI SCHOTT 1.744 44.8 R₈ = 25.11 4.7 17.5 S-LAM2 R₉ = 25.11

The invention described in the above detailed description is notintended to be limited to the specific form set forth herein, but, onthe contrary, is intended to cover such alternatives, modifications andequivalents as can reasonably be included within the spirit and scope ofthe appended claims.

What is claimed is:
 1. A magnification loupe carried by spectacleshaving a pair of lenses comprising: an eyepiece lens housing having atleast one eyepiece lens mounted therein, said eyepiece lens housingbeing smaller than a lens of said spectacles and including threadsthereon; an objective lens housing having at least one objective lensmounted therein and including a pin aperture and a pin received in saidpin aperture engaging said threads such that said objective lens housingis rotatably adjustable relative to said eyepiece lens housing to enablea distance between said eyepiece lens housing and said objective lenshousing to be varied.
 2. A magnification loupe according to claims,wherein said objective lens housing is removable to permit substitutionby a second objective lens housing carrying an objective lens ofdifferent magnification.
 3. A magnification loupe carried by spectacleshaving a pair of lenses comprising: an eyepiece lens housing having atleast one eyepiece lens mounted therein, said eyepiece lens housingbeing smaller than a lens of said spectacles and including threadsthereon; an objective lens housing having at least one objective lensmounted therein and including a pin aperture; and adjustable means formoving said objective lens housing relative to said eyepiece lenshousing to vary a distance between said objective lens housing and saideyepiece lens housing; an optic element disposed on said loupe forincreasing a light path length between said at least one objective lensand said at least one eyepiece lens; wherein said adjustable meansincludes a pin aperture in said objective lens housing, threads on saideyepiece lens housing opposing said pin aperture, and a pin received insaid pin aperture for engaging said threads.
 4. A magnification loupecarried by spectacles having a pair of lenses comprising: an eyepiecelens housing having at least one eyepiece lens mounted therein, saideyepiece lens housing being smaller than a lens of said spectacles andincluding threads thereon; an objective lens housing having at least oneobjective lens mounted therein and including a pin aperture; andadjustable means for moving said objective lens housing relative to saideyepiece lens housing to vary a distance between said objective lenshousing and said eyepiece lens housing; an optic element disposed onsaid loupe for increasing a light path length between said at least oneobjective lens and said at least one eyepiece lens, wherein said opticelement is a roof-penchan prism; and wherein said adjustable meansincludes a pin aperture in said objective lens housing, threads on saideyepiece lens housing opposing said pin aperture, and a pin received insaid pin aperture for engaging said threads.
 5. A magnification loupecarried by spectacles having a pair of lenses comprising: an eyepiecelens housing having at least one eyepiece lens mounted therein, saideyepiece lens housing being smaller than a lens of said spectacles andincluding threads thereon; an objective lens housing having at least oneobjective lens mounted therein and including a pin aperture; andadjustable means for moving said objective lens housing relative to saideyepiece lens housing to vary a distance between said objective lenshousing and said eyepiece lens housing; an optic element disposed onsaid loupe for increasing a light path length between said at least oneobjective lens and said at least one eyepiece lens wherein the opticelement is a roof-penchan prism that includes two prisms separated by aspacer having an aperture centered on an optical axis of said loop; andwherein said adjustable means includes a pin aperture in said objectivelens housing, threads on the surface of said eyepiece lens housingopposing said pin aperture, and a pin received in said pin aperture forengaging said threads.